callback_column not working for connected table in grocery crud

Question

I am trying to change column value using callback_column function.

$crud = new grocery_CRUD();
$crud -> set_table('booking');
//$crud->set_relation('room_id','rooms','name');
$crud->callback_column('room_id',array($this,'_visitor_details_popup')); 

This code workings well (_visitor_details_popup function return value to room_id)

$crud = new grocery_CRUD();
$crud -> set_table('booking');
$crud->set_relation('room_id','rooms','name');
$crud->callback_column('room_id',array($this,'_visitor_details_popup'));

This code NOT workings well (room_id not changing)

public function _visitor_details_popup($value, $row)
{

    $visitor_details=explode(',',$value);
    return '<a href="#">Name'.$visitor_details[1].'<a>'.'<div class="popup_content">Address'.$visitor_details[2].'Email'.$visitor_details[3].'</div>;
}

Is this a bug in grocery crud?? Any tricky way to solve it??

Answer 1

I got a trick. create a function and call it on callback_column parameter..

$crud = new grocery_CRUD();
$crud -> set_table('booking');
$crud->set_relation('room_id','rooms','name');
$crud->callback_column(unique_field_name('room_id'),array($this,'_visitor_details_popup')); verity 

function unique_field_name($field_name) 
{
    return 's'.substr(md5($field_name),0,8); //This s is because is better for a string to begin               with a letter and not with a number
}